The invention relates to an electrical machine, which has a housing, which has a stator with laminate layers, a rotor, whose shaft is mounted such that it can rotate via bearings positioned in bearing plates, and a liquid casing in the housing having meandering cooling channels.
In order to increase the power and torque, the principle of liquid or water cooling is used in electrical machines. In liquid-cooled electrical machines, in this case different principles of liquid cooling are used. The liquid permeates an extruded profile which is equipped with axial cooling channels, usually in the corner regions. The deflection of the liquid flow takes place in the separate bearing plates or by means of additional deflecting plates, which are fitted on the outside on the electrical machine.
Deflection in the bearing plates takes place by means of cast-in or drilled channels, and some of the tubes are also cast into the castings at the same time. Sealing at the bearing plates or deflecting plates takes place, owing to the construction, predominantly by means of surface sealing means, for example a flat gasket or fluids, and for this reason has an extremely complex design.
One further principle for cooling an electrical machine is inserting a cooling coil into grooves in the rear of the stator which are arranged in annular or meandering fashion. This results in complex fitting, and the heat transfer from the stator to the cooling coil is insufficient.
Furthermore, an arrangement of cooling collars around the housing of an electric motor is also known. The production of these cooling collars is very complex; the heat transfer from the heat sources of the electrical machine to the cooling collars is likewise extremely deficient.